Effectiveness of two treatments to promote tree regeneration: implications for forest restoration in the Isla del Coco National Park, Costa Rica

Introduction: Isla del Coco is the only island in the Eastern Tropical Pacific with humid tropical forests; 296 plant species are reported, of them, 22% are endemic. Their ecology is poorly understood. Deforestation and the introduction of rats, feral pigs and white-tailed deer are the primary agents of forest degradation. After more than 120 years, the deforested areas have never recovered the native forest. Objective: To analyse if the deforested area keeps its resilience, we evaluated the natural regeneration and ecological processes associated. Methods: From August 2016 to June 2018, we conducted a restoration experiment consisting of a randomized complete blocks design including vegetation cutting, vegetation uprooting and controls as treatments. Plots were protected with an exclusion fence to avoid herbivores. Results: There were no differences between plant cutting and uprooting in stimulating natural regeneration. We only recorded the seedlings of two tree species, 35 individuals of Cecropia pittieri and three of Sacoglottis holdridgei, both endemic. Their regeneration established during the first 15 months mainly. At the end of the experiment, the structure and composition of the vegetation changed from bushes dominated by Entada gigas (28%) and Clidemia strigillosa (12%) to grasses dominated by Paspalum conjugatum (39%). Entada gigas has a high recolonizing potential with a growing rate of 1.6±0.2m/month. Conclusions: As filters for restoration we determined herbivores, which pose a strong negative impact in the development of the forest; the exhausted seed bank of tree species and scarce or null seed dispersion.

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Secondary seed removal in a degraded forest habitat in Madagascar

Scientific Reports ◽

10.1038/s41598-021-96306-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Paula M. A. Fiedler ◽

Alice De Lapparent ◽

Jeremie Razafitsalama ◽

Justin Sanamo ◽

Kim J. E. Steffens ◽

...

Keyword(s):

Seed Dispersal ◽

Seed Predation ◽

Tree Species ◽

Natural Regeneration ◽

Forest Restoration ◽

Forest Degradation ◽

Degraded Forest ◽

Seed Removal ◽

Forest Habitat ◽

Removal Experiments

AbstractForest restoration is a prime goal within the 2021–2030 UN “Decade of Ecosystem Resoration”. As part of these activities, natural regeneration has to be promoted for biological as well as for economic reasons. For this, the processes of seed dispersal, seed predation and germination have to be understood in the original as well as in degraded vegetation formations. We used seed removal experiments to assess post-dispersal processes that influence recruitment along a gradient of forest degradation in Madagascar analyzing seeds of three animal dispersed tree species. The percentage of seeds consumed or dispersed, declined from forest (28.6%) to degraded forest (17.2%) to savanna (10.8%). Only three out of 1080 seeds were cached and remained intact during the 14-day experiment. All three seeds were cached in the forest habitat and none in the degraded forest and savanna. The low percentage of seeds removed may be due to the lack of endemic rodents caching seeds, as only introduced rats were recorded in the area. The species-poor fauna of potential secondary seed dispersers of the region and especially in the degraded areas might represent an obstacle for diverse regeneration in degraded regions of Madagascar.

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Factors Influencing the Natural Forest Regeneration at Khadimnagar National Park, Bangladesh

Borneo Journal of Resource Science and Technology ◽

10.33736/bjrst.3437.2021 ◽

2021 ◽

Vol 11 (1) ◽

pp. 73-83

Author(s):

MAHEDI HASAN LIMON ◽

SAIDA HOSSAIN ARA ◽

MOHAMMAD GOLAM KIBRIA

Keyword(s):

Species Richness ◽

Bulk Density ◽

Total Variation ◽

Soil Ph ◽

Tree Species ◽

Natural Regeneration ◽

National Park ◽

Canopy Openness ◽

Site Factors ◽

Tree Species Richness

Natural regeneration is an indicator of a healthy forest, hence, understanding the influence of site factors on natural regeneration is a significant concern for ecologists. This work aimed to assess the impact of site factors on natural tree regeneration at Khadimnagar National Park (KNP). Biotic factors (tree density, tree species richness, and basal area), physical factors (elevation, canopy openness), and soil properties (bulk density, moisture content, soil pH, organic matter, sand, silt, and clay) data were investigated from 71 sample plots to examine their effects on natural regeneration density and richness in KNP. Stepwise multiple linear regression analysis was done to predict both regeneration density and regeneration richness. The results showed that soil pH (p<0.001), canopy openness (p<0.001), tree species richness (p<0.01), and bulk density (p<0.01) had a significant effect on regeneration density, explaining 42% of the total variation. Regeneration richness was driven by four factors: tree species richness (p<0.01), soil pH (p<0.001), elevation (p<0.01), and canopy openness (p<0.01) with a model that explained 60% of the total variation. This study observed that soil pH, tree species richness, and canopy openness are the main controlling factors that influenced both the density and richness of regenerating species in KNP. Therefore, these findings have implications for natural resource management, especially in selecting suitable silvicultural systems in a tropical forest under protected area management where enhanced tree cover and conservation of biodiversity are needed.

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Análise da Expansão Antrópica na Região Oeste do Município de Resende – RJ, em Relação ao Parque Nacional do Itatiaia

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v13.3.p928-940 ◽

2020 ◽

Vol 13 (3) ◽

pp. 928

Author(s):

Camila Mendes Dos Santos ◽

Cláudio Lindenberg De Freitas ◽

Igor Crabi De Freitas ◽

Ismael Aparecido Da Silva ◽

Nivea Adriana Dias Pons ◽

...

Keyword(s):

National Park ◽

Negative Impact ◽

Buffer Zone ◽

Temporal Analysis ◽

Google Earth ◽

Western Region ◽

Ecological Processes ◽

Parque Nacional Do Itatiaia ◽

The Western Region ◽

Surrounding Areas

O Parque Nacional do Itatiaia (PNI) é uma Unidade de Conservação de proteção integral, que tem por objetivo preservar ambientes aquáticos e terrestres da região da mata atlântica em virtude de sua beleza e raridade. A conservação do PNI depende diretamente das áreas ao redor e o uso irregular destas áreas circunvizinhas impacta negativamente nos processos ecológicos do parque. Observando essa problemática o presente estudo visa analisar a expansão antrópica na região oeste do município de Resende – RJ, em relação ao PNI. Realizaram-se pesquisas bibliográfica e documental sobre o Plano Diretor (PD) do município de Resende e o Plano de Manejo (PM) do PNI. Através de processos de geoprocessamento com base na legislação vigente, analisou-se documentos cartográficos processados a partir da vetorização de shapefiles no Arcgis 10.2 e análise temporal nos anos de 2003, 2013 e 2017 dos dados disponíveis no Google Earth. Os resultados demonstram diminuição das pastagens e aumento do número de edificações ao longo dos anos de estudo. O PM do PNI e o PD de Resende consideram o entorno do parque como uma região sujeita a restrições de atividades humanas, com o intuito de minimizar os impactos negativos ao parque. Contudo, por falta de integração entre os planos alguns pontos se tornam divergentes, muito em decorrência do PD não levar em consideração a zona de amortecimento (ZA) do PNI. Conclui-se o controle da ação antrópica na região é fundamental para garantia e preservação do PNI no município de Resende, a fim de promover um desenvolvimento sustentável. Analysis of the anthropic expansion in the western region of the municipality of Resende - RJ, in relation to the Itatiaia National Park The National Park of Itatiaia (PNI) is a Conservation Unit of integral protection, whose objective is to preserve aquatic and terrestrial environments of the region of the Atlantic forest due to its beauty and rarity. The conservation of the PNI depends directly on the surrounding areas and the irregular use of the surrounding areas has a negative impact on the ecological processes of the park. Observing this problem, the present study aims to analyze the anthropic expansion in the western region of the city of Resende - RJ, in relation to the PNI. Bibliographical and documentary research on the Master Plan (PD) of the municipality of Resende and the Management Plan (PM) of the PNI were carried out. Through geoprocessing processes based on the current legislation, we analyzed cartographic documents processed from the vectorization of shapefiles in Arcgis 10.2 and temporal analysis in the years 2003, 2013 and 2017 of the data available in Google Earth. The results demonstrate a reduction of pastures and an increase in the number and buildings throughout the study years. The PM of the PNI and the PD of Resende consider the surroundings of the park as a region subject to restrictions of human activities, in order to minimize the negative impacts to the park. However, due to lack of integration between the plans some points become divergent, much as the PD does not take into account the buffer zone (ZA) of the PNI. The control of the anthropic action in the region is fundamental to guarantee and preserve the PNI in the municipality of Resende, in order to promote a sustainable development. Keywords: Expansion; Geoprocessing; Protection Area.

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Thorny Shrubs Limit the Browsing Pressure of Large Herbivores on Tree Regeneration in Temperate Lowland Forested Landscapes

Sustainability ◽

10.3390/su11133578 ◽

2019 ◽

Vol 11 (13) ◽

pp. 3578 ◽

Cited By ~ 2

Author(s):

Salek ◽

Harmacek ◽

Jerabkova ◽

Topacoglu ◽

Machar

Keyword(s):

Tree Species ◽

Forest Restoration ◽

Landscape Planning ◽

Military Training ◽

Tree Regeneration ◽

Deciduous Tree ◽

Tree Seedlings ◽

Shrub Species ◽

Large Herbivore ◽

Large Herbivores

Thorny shrubs are considered as an important driver in the natural development of temperate forest structures, particularly in European lowland forests. We assessed the current role of thorny shrubs in the regeneration of deciduous tree species under heavy browsing pressure in a central European temperate forested landscape. The study’s military training area offered a unique opportunity to investigate the processes in which deciduous tree seedlings grew under thorny shrubs and in the close vicinity of thorny shrubs in a landscape with a high density of large herbivores (red deer and sika deer). We assessed the number of seedlings, species composition, seedling height, and degree of browsing damage, and their relationship to study plots elevation, thorny shrub species, coverage, and height. The regenerated tree seedlings were mostly detected as common ash (Fraxinus excelsior) and wild cherry (Cerasus avium). The species of thorny shrubs were blackthorn (Prunus spinosa), hawthorn (Crataegus sp.), and wild rose (Rosa sp.). We found that the thorny shrubs protected the tree seedlings from browsers to a large extent. However, the effects of thorny shrubs on the tree seedlings' characteristics varied among the shrub species. While results revealed significant effects of hawthorn and wild rose on the tree seedlings' abundance and survival, blackthorn’s negative effect of shading the tree seedlings outweighed its protective role. These results indicated a possible mechanism that enabled the regeneration of deciduous tree species under large herbivore pressure. These results can be applied in the landscape planning and forest management of deciduous tree regeneration and forest restoration in temperate forested lowland landscapes, where high densities of large herbivores (without the presence of large predators) usually occur.

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The savanna tree Acacia polyacantha facilitates the establishment of riparian forests in Serengeti National Park, Tanzania

Journal of Tropical Ecology ◽

10.1017/s0266467408005683 ◽

2009 ◽

Vol 25 (1) ◽

pp. 31-40 ◽

Cited By ~ 11

Author(s):

Gregory J. Sharam ◽

A. R. E. Sinclair ◽

Roy Turkington ◽

Aerin L. Jacob

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

National Park ◽

Seedling Survival ◽

Forest Tree ◽

Riparian Forests ◽

Forest Trees ◽

Grass Cover ◽

Serengeti National Park ◽

Acacia Polyacantha

Abstract:Forests are being converted to grasslands and croplands across Africa and natural regeneration of forests is typically poor. In Serengeti National Park, Tanzania, the savanna tree species Acacia polyacantha established in riparian grasslands and forest trees subsequently established within these stands. We examined the conditions for establishment of: (1) A. polyacantha and (2) riparian (non-Acacia) forests. Fire was excluded from three grassland areas for 5 y allowing A. polyacantha to establish during 1999 when dry-season rainfall was high. The seedlings of forest tree species did not establish in grasslands, but were found in large A. polyacantha stands (> 0.3 ha) with reduced grass cover (< 10%), higher cover of herbs (> 80%) and thorny shrubs (> 90%). Seeding survival was high in large stands (0.87 y−1), but declined in artificial canopy gaps due to the ingrowth of grasses (0.21 y−1) and subsequent fires (0.07 y−1). Shrub removal also reduced seedling survival (0.46 y−1) due to browsing by antelope. We propose that: (1) A. polyacantha establishes in pulses perhaps as infrequently as twice per century, and (2) riparian forests in Serengeti have established via facilitation under larger stands where shade excludes grass, and therefore fires and thorny shrubs exclude browsers.

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Advance of Urochloa decumbens (Stapf) R.D. Webster (Poaceae) on remaining native forest in the Serra da BODOQUENA NATIONAL PARK

Biodiversidade Brasileira - BioBrasil ◽

10.37002/biobrasil.v10i2.1481 ◽

2020 ◽

pp. 148-157

Author(s):

José Guilherme Dias De Oliveira ◽

Luiz Fernando Duarte De Moraes ◽

Tânia Sampaio Pereira ◽

Geraldo Alves Damasceno Junior

Keyword(s):

Natural Regeneration ◽

National Park ◽

Invasive Alien Species ◽

Habitat Destruction ◽

Native Forest ◽

Natural Forests ◽

Fire Control ◽

Exotic Grasses ◽

Forest Remnants ◽

Urochloa Decumbens

The replacement of native forest by exotic grasses for pasture formation is a process that involves habitat destruction followed by the introduction of invasive alien species. The Serra da Bodoquena National Park covers an area of 77,021.58ha, comprising natural forests and remnants of abandoned pastures, which represent a threat to local biodiversity conservation. This study analyzed the dynamics of Urochloa decumbens–dominated matrix on remnants of native Deciduous Seasonal Forest within the Park, over 35 years, using satellite images, evaluating natural regeneration trend. The Urochloa matrix covers 1,268.9 (36.9%) of the 3,434.50 hectares study area. Our results indicate that the Urochloa matrix expanded over the native forest remnants, likely due to the occurrence of fire close to the forest edges, which may help natural regeneration failing. 8 months after a fire in 2013, the area of the grass-dominates matrix was found to replace 203.1 hectares over the forest. In this context, restoration actions are demanded, especially those that target fire control.

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Inventory of native and mother trees in Key Biodiversity Areas of Cebu Island, Philippines for species selection in local reforestation programs

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d221105 ◽

2021 ◽

Vol 22 (11) ◽

Author(s):

Edgardo P. Lillo ◽

ARCHIEBALD B. MALAKI ◽

STEVE MICHAEL T. ALCAZAR ◽

RAAMAH ROSALES ◽

BERNARDO R. REDOBLADO ◽

...

Keyword(s):

Tree Species ◽

Native Species ◽

Forest Restoration ◽

Habitat Preferences ◽

Forest Degradation ◽

Species Selection ◽

Adult Trees ◽

Native Tree ◽

Native Tree Species ◽

Planting Materials

Abstract. Lillo EP, Malaki AB, Alcazar SMT, Rosales R, Redoblado BR, Diaz JLB, Pantinople EM, Buot Jr. IE. 2021. Inventory of native and mother trees in Key Biodiversity Areas of Cebu Island, Philippines for species selection in local reforestation programs. Biodiversitas 22: 4740-4749. Forest restoration is the counterforce of deforestation and forest degradation. Yet, despite promoting natural recovery after forest harvest, afforestation and reforestation efforts, tropical forest ecosystems still experience a poor ratio of forest loss to forest gain. The study assessed the native tree species and potential mother trees in different Cebu Island Key Biodiversity Areas (KBAs) as well as their distribution and habitat preferences which can be used in local reforestation programs. A vegetation survey was conducted in three KBAs in Cebu Island, namely Nug-as forest, Mount Lantoy and Mount Capayas to inventory all native species. Assessment based on the phenotypic characteristics of adult trees was also conducted for indicating mother trees. This study in Cebu Island KBAs recorded a total of 292 species, categorized into 125 families and 203 genera, which can be classified into native trees (210), vines and lianas (18), shrub (37), and herbs (27). Out of the 292 species, 214 were recorded in Nug-as forest, 172 in Mount Lantoy, and 145 in Mount Capayas. Of the 210 native tree species, Nug-as forest had 145 species, Mount Lantoy 131 species, and Mount Capayas 109 species. A total of 241 mother trees were identified in the three KBAs, corresponding to 77 species in which Nug-as forest had 143 trees correspond to 52 species, Mount Lantoy had 68 trees correspond to 29 species, and Mount Capayas had 31 trees correspond to 6 species. Such native tree species are recommended for reforestation programs as planting materials that could reduce the risks of failure due to its high adaptability to the environment.

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Natural regeneration potential of Madhupur National Park, Bangladesh

Bangladesh Journal of Botany ◽

10.3329/bjb.v49i4.52515 ◽

2020 ◽

Vol 49 (4) ◽

pp. 989-996

Author(s):

Md Rayhanur Rahman ◽

MK Hossain ◽

Md Akhter Hossain ◽

Mohammad Emran Hasan

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

National Park ◽

Alien Invasive Species ◽

Importance Value Index ◽

Importance Value ◽

Height Range ◽

Shorea Robusta ◽

Extensive Collection ◽

Litsea Glutinosa

Natural regeneration is an essential tool to evaluate the overall health of a forest ecosystem. Natural regeneration of the tree species in Madhupur National Park showed 47 regenerating tree species among which Shorea robusta has maximum density (18,046 seedlings per ha) followed by Aporosa sp., whereas minimum density (19 seedling per ha) was recorded for Cassia nodosa, Litsea glutinosa, Grewia asiatica and Syzygium cumini, respectively. Relative density, relative frequency and relative abundance were estimated to assess the Importance Value Index (IVI) of the seedlings of different tree species. IVI of S. robusta was highest (66.25 out of 300) followed by Mallotus philippensis (27.33). G. asiatica, Derris robusta, and L. glutinosa showed the lowest IVI (0.93) among the regenerating tree species. Distribution of seedlings into different height classes showed that maximum number (31.4%) of seedlings in the height range of 50 - <100 cm. Among the recorded seedlings, Protium serratum showed maximum (11%) recruitment success. Alien invasive species, pineapple and banana based participatory agroforestry, frequent occurrence of fire, extensive collection of fuelwood and litter are the potential threats to the natural regeneration of Madhupur National Park.

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Tree Regeneration Characteristics in Limestone Forests of the Cat Ba National Park, Vietnam

10.21203/rs.3.rs-244706/v1 ◽

2021 ◽

Author(s):

Van Vien Pham ◽

Christian Ammer ◽

Peter Annighöfer ◽

Steffi Heinrichs

Keyword(s):

Species Richness ◽

Species Diversity ◽

Tree Species ◽

National Park ◽

Forest Regeneration ◽

Tree Regeneration ◽

Conservation Strategy ◽

Tree Species Diversity ◽

Site Factor ◽

Overstory Tree

Abstract Background: Forest regeneration is decisive for future forest development and therefore of major concern to forest ecologists. The ability of overstory tree species to regenerate successfully is important for the preservation of tree species diversity and its associated flora and fauna. This study investigated forest regeneration dynamics in the Cat Ba National Park, a biodiversity hotpot in Vietnam. Data was collected from 90 sample plots and 450 sub-sample plots in the regional limestone forests. We compared species richness between the regeneration and overstory tree layers and examined the effect of environmental factors on the occurrence of regeneration. We developed five ratios to relate overstory and regeneration richness and diversity. Results: We found 97 tree species in the regeneration layer compared to 136 species in the overstory layer. Average regeneration density was 3,764 ± 1,601 per ha. Around 70% of the overstory tree species generated offspring. Of the tree species threatened according to The International Union for Conservation of Nature’s Red List of Threatened Species, only 36% were found in the regeneration layer. A principal component analysis provided evidence that the regeneration of tree species was linked to terrain factors (percentage of rock surface, slope) and soil properties (Cation exchange capacity, pH, humus content, soil moisture, soil depth). Contrary to our expectations, the prevailing light conditions (total site factor, gap fraction, openness, indirect site factor, direct site factor) had no influence on regeneration density and composition, probably due to the small gradient in light availability. Conclusion: We conclude that tree species richness in Cat Ba National Park appears to be declining at present. We suggest similar investigations in other biodiversity hotspots to learn whether the observed trend is a global phenomenon. In any case, a conservation strategy for the threatened tree species in the Cat Ba National Park needs to be developed if tree species diversity is to be maintained.

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Tree regeneration characteristics in limestone forests of the Cat Ba National Park, Vietnam

BMC Ecology and Evolution ◽

10.1186/s12862-021-01957-9 ◽

2022 ◽

Vol 22 (1) ◽

Author(s):

Van Vien Pham ◽

Christian Ammer ◽

Peter Annighöfer ◽

Steffi Heinrichs

Keyword(s):

Species Diversity ◽

Tree Species ◽

National Park ◽

Humus Content ◽

Tree Regeneration ◽

Conservation Strategy ◽

Tree Species Diversity ◽

Site Factor ◽

Overstory Tree ◽

Threatened Tree Species

Abstract Background The ability of overstory tree species to regenerate successfully is important for the preservation of tree species diversity and its associated flora and fauna. This study investigated forest regeneration dynamics in the Cat Ba National Park, a biodiversity hotspot in Vietnam. Data was collected from 90 sample plots (500 m2) and 450 sub-sample plots (25 m2) in regional limestone forests. We evaluated the regeneration status of tree species by developing five ratios relating overstory and regeneration richness and diversity. By examining the effect of environmental factors on these ratios, we aimed to identify the main drivers for maintaining tree species diversity or for potential diversity gaps between the regeneration and the overstory layer. Our results can help to increase the understanding of regeneration patterns in tropical forests of Southeast Asia and to develop successful conservation strategies. Results We found 97 tree species in the regeneration layer compared to 136 species in the overstory layer. The average regeneration density was 3764 ± 1601 per ha. Around 70% of the overstory tree species generated offspring. According to the International Union for Conservation of Nature’s Red List, only 36% of threatened tree species were found in the regeneration layer. A principal component analysis provided evidence that the regeneration of tree species was slightly negatively correlated to terrain factors (percentage of rock surface, slope) and soil properties (cation exchange capacity, pH, humus content, soil moisture, soil depth). Contrary to our expectations, traces of human impact and the prevailing light conditions (total site factor, gap fraction, openness, indirect site factor, direct site factor) had no influence on regeneration density and composition, probably due to the small gradient in light availability. Conclusion We conclude that the tree species richness in Cat Ba National Park appears to be declining at present. We suggest similar investigations in other biodiversity hotspots to learn whether the observed trend is a global phenomenon. In any case, a conservation strategy for the threatened tree species in the Cat Ba National Park needs to be developed if tree species diversity is to be maintained.

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